ABSTRACT
OBJECTIVE: To compare the effects of placebo and GLA on the course of mild diabetic neuropathy over 1 yr. RESEARCH DESIGN AND METHODS: We entered 111 patients with mild diabetic neuropathy from seven centers into a randomized, double-blind, placebo-controlled parallel study of GLA at a dose of 480 mg/day. MNCV, SNAP, CMAP, hot and cold thresholds, sensation, tendon reflexes, and muscle strength were assessed by standard tests in upper and lower limbs. RESULTS: For all 16 parameters, the change over 1 yr in response to GLA was more favorable than the change with placebo, and for 13 parameters, the difference was statistically significant. Sex, age, and type of diabetes did not influence the result, but treatment was more effective in relatively well-controlled than in poorly-controlled diabetic patients. CONCLUSIONS: GLA had a beneficial effect on the course of diabetic neuropathy.
Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Diabetic Neuropathies/drug therapy , Linolenic Acids/therapeutic use , Analysis of Variance , Diabetes Mellitus, Type 1/physiopathology , Diabetes Mellitus, Type 2/physiopathology , Diabetic Neuropathies/physiopathology , Double-Blind Method , Female , Humans , Linolenic Acids/adverse effects , Male , Middle Aged , Motor Neurons/drug effects , Motor Neurons/physiology , Neural Conduction/drug effects , Neurologic Examination , Neurons, Afferent/drug effects , Neurons, Afferent/physiology , Reflex , gamma-Linolenic AcidABSTRACT
Recently a defect in the function of the enzyme delta-6-desaturase has been discussed as a major factor in the development of atopic eczema. Delta-6-desaturase is responsible for the conversion of linoleic acid to gamma linolenic acid. Several plants, including evening primrose, are known to be fairly rich in gamma linolenic acid. Hence, substitution of gamma linolenic acid in patients prone to developing atopic eczema seems like a feasible concept. During the last few years different clinical trials have been performed. Controlled trials following a parallel study design showed marked improvement in atopic eczema. Patients treated with the drug showed less inflammation, dryness, scaling and overall severity compared to controls. Although these findings have been supported by meta-analysis, there is still conflicting evidence in trials based on a crossover design alone, demonstrating a decrease in itching. At present, evening primrose oil in doses used for the treatment of atopic eczema is considered safe. However, still more trials addressing both efficacy and safety are needed to make a final decision.
Subject(s)
Dermatitis, Atopic/drug therapy , Dermatologic Agents/administration & dosage , Fatty Acids, Essential/administration & dosage , Administration, Oral , Alprostadil/deficiency , Dermatologic Agents/adverse effects , Fatty Acids, Essential/adverse effects , Humans , Linoleic Acids , Linolenic Acids/administration & dosage , Linolenic Acids/adverse effects , Oenothera biennis , Plant Oils , gamma-Linolenic AcidABSTRACT
Small amounts of linolenic acid are ubiquitous in human food but only a few foodstuffs contain sizable amounts, namely some plant oils, butter and fish; in marine fish, linolenic acid is accomplished by eicosapaentaenoic acid, highly exceeding linolenic acid in quantity. Of the linolenic acid ingested, some is incorporated into phospholipids and cholesteryl esters, very little is elongated and eventually converted to prostaglandins; probably most linolenic acid is used as fuel. Polyunsaturated fatty acids of the (n-3)-series should no longer be considered to be similar with respect to their metabolic fate and their effects. In particular, results from experiments with "eskimo diets" may not be applied to considerations of linolenic acid. There may be a small dietary requirement for linolenic acid, possibly only for growing children; yet it is prudent to recommend diets which are not devoid of linolenic acid, especially in formula diets or parenteral nutrition. Some experiments suggest that high doses of linolenic acid exert untoward effects by inhibiting prostaglandin synthesis of the 1- and 2-series. The ratio between linoleic and linolenic acid in relevant experiments was such that only excessive use of linseed oil could produce them under conventional dietary conditions. Still it must be considered prudent to keep the linolenic acid content of foods well below that of linoleic acid.
Subject(s)
Dietary Fats, Unsaturated/metabolism , Linolenic Acids/metabolism , Dietary Fats, Unsaturated/adverse effects , Humans , Linolenic Acids/adverse effects , alpha-Linolenic AcidABSTRACT
Male Wistar rats were fed semipurifed diets containing 20% fat for 25 weeks. Ten different oils or oil blends were employed, including rapessed oils, simulated rapeseed-type oils, and modified rapeseed-type oils. Safflower, soybean, and hydrogenated coconut oils served as control oils. Histopathological examination of the cardiac tissue was conducted at the end of the study and an incidenceseverity rating assigned to the lesions induced by each fat. Oils containing high levels of erucic acid (26-30%) induced the most severe cardiac necrosis, irrespective of the source of erucic acid (rapeseed oil or nasturtium oil). Increasing the linoleic: :linolenic acid ratio of the high erucic oils to that of soybean oil failed to reduce necrosis, but the absence of linolenic acid from a high erucic acid oil blend resulted in a markedly reduced lesion incidenceseverity rating, comparable to those obtained for low erucic acid rapessed oil and soybean oil which were similar. Lowest lesion incidence was obtained with safflower oil and hydrogenated coconut oil. We have postulated that linolenic acid plays a role in the etiology of cardiac necrosis observed when rats are fed diets containing low erucic acid rapeseed oils.
